The Water Food Energy Nexus

With earth’s growing population and increasing stresses on the environment, the nexus of water, energy, and food security has become a central issue, reflecting the tradeoffs and interactions between these core sectors. The Earth Institute is working on many initiatives to better understand these interactions and develop sustainable, integrated solutions.

The Earth Institute’s Columbia Water Center (CWC) studies how the water, food, and energy sectors are interrelated and how climate affects these relationships. On the applied side, the CWC aims to promote water and energy savings in the agricultural sector in water-stressed farming regions; it has been worked with governments in India to reform existing energy subsidies by incentivizing electricity savings of both water and energy without decreasing crop yields. The CWC also develops seasonal forecasts to guide decision-making in the water and energy sectors. It is pioneering the implementation of low-cost soil moisture and nitrogen sensors to improve irrigation efficiency and reduce fertilizer use and groundwater pollution. On the theoretical side, the CWC has developed hydrologic models that include human activities–specifically crop growth and irrigation– to identify water-stressed regions and evaluate the role of climate variability on irrigation demands and water stress.

The Agriculture and Food Security Center (AgCenter) is also pioneering ways to increase crop yields and improve nutrient management. SoilDoc is a portable, on-site soil testing kit that provides tailored input recommendations for farmers. The kit uses an Android device to transmit soil information electronically, allowing extension workers to make on-the-spot diagnoses of soil constraints and targeted recommendations to advise farmers in near-real-time. With this information, farmers will only place expensive fertilizers where needed, reducing their costs. By increasing efficiency and yields, SoilDoc’s tailored recommendations may also minimize nutrient losses and improve food security.

The Center for International Earth Science Information Network (CIESIN) is collaborating with the Ag Center, the Columbia Global Center | East Africa, and other partners to develop the Africa Soil Information Service (AfSIS), with funding from the Bill & Melissa Gates Foundation. AfSIS is developing continent-wide digital soil maps and tools to help increase agricultural production and improve food security sustainably. CIESIN is helping to incorporate remote sensing data from satellites and provide the data infrastructure needed to reach local farmers, extension agents, national agencies, and other users.

The UN’s Sustainable Development Solutions Network (SDSN), an Earth Institute affiliate, also considers the water/food/energy nexus of primary importance. One of its initiatives aims to achieve energy access for all. Every objective in the fight against poverty depends on energy, including food security, increasing incomes, access to safe water, disease control, maternal and child health, and universal schooling. The absence of energy access therefore represents a major obstacle to eradicating poverty, and to social and economic development. The need for energy access is especially great in rural areas of Sub-Saharan Africa, where barriers to such access include lack of energy resources, lack of access to available energy and the prohibitive cost of energy from some sources. Developing energy resources and electricity infrastructure is essential for ensuring energy access.

However, the want of access to a national grid no longer prohibits having energy in Sub-Saharan Africa. Last year the SDSN began implementing a project in the region evaluating potential pathways for increasing access to electricity and studying the feasibility of deploying solar-powered minigrids, as in the Shared Solar project (see below). Under this initiative, led by Eni, the Italian international energy company, the SDSN will evaluate potential pathways for increasing access to electricity in Sub-Saharan Africa, furthering its goals of promoting sustainable development solutions globally. Eni has provided initial funding of $700,000 for the researchers, and plans to then invest in the identified pathways. The project will coordinate closely with the UN system and its new Sustainable Energy for All initiative. Once such projects are identified, it is intended for that the study be made publicly available in order for private sector companies, donors, countries, and investors to take the lead in implementing them.

The concept of Shared Solar was pioneered by Columbia University professor of engineering Vijay Modi; it consists of a sub-metering system for shared solar energy, which involves a small piece of hardware that recognizes a code from a prepurchased card, allowing an individual to spend only $5 a month for energy. Shared Solar systems have been working in Mali and Uganda successfully for more than 4 years, and there are plans to expand.

The grant further reinforces the Sustainable Development Solutions Network and the Earth Institute’s shared commitment to achieving the United Nations Millennium Development Goals in Africa through initiatives that help local communities gain access to basic energy services while assuring sustainable resource management.